On Monday, it was revealed one of the main gambling houses – Ladbrokes – had bumped Alice as a name favourite for Mary (with odds of 7-1).
Paddy Power had also slashed odds of the baby being called Mary from 12-1 to 3-1, while suspending all bets on William and Kate's third child being a girl. After Mary, Ladbrokes has Alice and Victoria at odds of 8-1, followed by Alexandra at 16-1. Albert and Arthur both stand at 12-1 for a baby boy.
"We can't quite put our finger on the link between Mary and the North West, but the overwhelming support means we have a new favourite in the royal baby name market," Jessica Bridge, of Ladbrokes, said. "Punters are convinced the Duke and Duchess are expecting another little girl, and obviously it would be a lovely touch to honour Her Majesty's grandmother, but it will be interesting to see if any boys' names are backed over the coming weeks before the birth."
READ MORE: Royal baby names from A to Z
Mary is a very traditional moniker with royal connections. It is one of the Queen's middle names and was also her grandmother's name – Queen Mary – who was Mary of Teck and married to George V.
Alice was once again the bookies' favourite when Kate was pregnant with her daughter in 2015. The pretty name would be a nod to Queen Victoria's second daughter, Alice Maud Mary. The late royal was famous for her compassionate nature and relentless advocacy of women's rights – two qualities that would be encouraged in a modern princess.